Yes, the Commander will control PX-8 Plus, but it is a little different than previous switchers. PX-8 Plus will need to be set to have Program Changes enabled and to listen for them on MIDI Channel 1 in order to work with the Commander.

This is done as follows:

Enable Program Change
1. Hold button 1 while powering up the PX-8 Plus (All LEDs will flash).
2. Release button 1.
In this program mode LEDs 1 and 2 indicate Program Change and Control Change Enable.
3. Set LED #1 to On.
4. Power down the PX-8 Plus.

If you will be in the all Instant Access mode, saving presets will be done as follows:
1. Press the desired Commander preset.
2. Press the combination of PX-8 Plus loop you want on for this preset.
3. Press PX-8 Plus buttons 1 and 6 at the same time to save the preset. (All LEDs will alternate flashing to confirm the save.)

JohnClark wrote:
If you will be in the all Instant Access mode, saving presets will be done as follows:
1. Press the desired Commander preset.
2. Press the combination of PX-8 Plus loop you want on for this preset.
3. Press PX-8 Plus buttons 1 and 6 at the same time to save the preset. (All LEDs will alternate flashing to confirm the save.)

I hope that helps!

I see the Commander has the " store " button.
Is it possible to save the preset pressing the " store " button instead of PX-8 PLUS buttons 1 & 6 ?

The PX-8 Plus doesn't respond to the Store button on the Commander the way the older Pedal Switchers, and original PX-8 did. The PX-8 Plus will only respond to the Program Change each Commander Preset button sends. Storing the preset needs to be done on the PX-8 Plus itself.